This blog is dedicated to an economic view of the environment, and my essays here typically feature analyses of existing or proposed policies, with a look to the future, particularly in the realm of global climate change. Today, however, I take a look back, with an examination of the early history of deliberations in the U.S. government about climate change.

Of course, the history of climate change science goes back at least to Svante Arrhenius, the Nobel Prize-winning Swedish physicist and chemist, who in 1896 calculated how increased concentrations of atmospheric carbon dioxide (CO2) would increase the Earth’s temperature through the greenhouse effect, a finding that was picked up many years later by Guy Stewart Callendar, Charles David Keeling, Roger Revelle, and others. But my focus is not on the history of the science, but on a very specific dimension of the policy history, namely the history of discussions within the U.S. government regarding climate change and potential policy responses.

Some might think that the starting point would be the 1988 Congressional hearings – led by U.S. Senators Timothy Wirth and Albert Gore – which the New York Times covered in a long article. That was during the last year of the Reagan administration, but the story really begins more than two decades earlier – in 1965.

Remarkably, the report included a 23-page discussion of the climatic effects of increased concentrations of atmospheric carbon dioxide (CO2), due to the combustion of fossil fuels, and – interestingly enough – concluded with a proposal for research on a specific approach to responding, namely with what is now called “geoengineering.” Below is the table of contents of that section of the report – on “Atmospheric Carbon Dioxide,” and you can read that section of the report here.

In his introduction to the report, President Johnson emphasized that “we will need increased basic research in a variety of specific areas,” and then went on to state: “We must give highest priority of all to increasing the numbers and quality of the scientists and engineers working on problems related to the control and management of pollution.” What a contrast with the anti-science approach of the current resident of the White House!

From the perspective of 2018, as we enter the second year of the Trump administration, it may – or may not – be comforting to recognize that scientific and even policy attention by the White House to climate change goes back more than five decades, to the administration of Lyndon Johnson. Since then, there have surely been ups and downs – through the administrations of Presidents Ford, Carter, Reagan, Bush (I), Clinton, Bush (II), and Obama, but the current administration is an outlier in its utter disdain for sound science and related hostility to sensible public policy (in this and other domains).

The list of Presidential administrations above should remind us that whether a single four-year term or the maximum eight years, administrations are relatively short-lived when judged in historical context. And they tend to swing back and forth between the two political parties.

Our moderator from the Chinese government then introduced me to speak, and as I listened with headphones to the simultaneous translation, I heard him say, “And now Harvard’s Professor Stavins will bring us some good news from the United States.” I was dumbfounded. What could I possibly say? I walked to the lectern, sipped some water, took a deep breath, and said to the audience, “When you get to be my age, you recognize that four years is not a long time!”

That will have to suffice as an “optimistic” conclusion to today’s essay.

The ultimate purpose of the newly announced Chinese trading system is to help the country meets its emissions and renewable energy targets which are part of its Nationally Determined Contribution under the Paris Agreement, in particular, peaking its CO2 emissions by 2030, and achieving 20% of the country’s energy supply from renewables. Note that coal currently accounts for 65% of China’s electricity generation. Wind and solar capacity have been growing rapidly, but still account for only 4% and 1% of generation, respectively.

The Chinese carbon market will double the share of global CO2 emissions covered by worldwide carbon-pricing systems to almost 25 percent. For this and other reasons, the December announcement was greeted with excited praise from climate activists (but simultaneously with disregard and skepticism from conservative opponents of climate action). The most reasonable assessment, however, is between those two extremes, as I explain in this essay. That said, the December announcement by China of its plan to develop and launch a nationwide CO2 trading system is an important landmark on the long road to addressing the threat of global climate change.

Some Brief History for Context

In 2011, China’s 12th Five-Year Plan (2011-2015) first included a statement about the government’s intention to develop – gradually – a nationwide carbon market. Subsequently, in 2013 and 2014, seven pilot emissions trading programs were launched in the cities of Beijing, Chongqing, Shanghai, Shenzhen, and Tianjin, plus two provincial systems in Guangdong and Hubei. In total, these covered some 3,000 sources, with total annual CO2 emissions of 1.4 billion tons. The designs of the systems were intentionally varied, to facilitate learning, and allowance prices ranged from $3 to $10 per ton of CO2.

The rate-based approach is intended to have a smaller impact on marginal production costs than the mass-based cap-and-trade approach, and thereby is likely to have a smaller impact on the price of products (whether electricity or manufactured goods). This is the motivation for using this approach in an output-based updating allocation, as described above, and it carries with it the parallel disadvantage of insulating consumers from (some of) the social costs of their consumption decisions. The problem is exacerbated in the case of China’s evolving system because the performance standards (emission benchmarks) are set not only by sector, but by various categories of electricity production within the sector. As some categories are, in effect, subsidized by other categories, the cost-effectiveness of the overall system declines. There is a lack of incentive for the carbon market to move energy consumption from coal to natural gas, for example, because of the multi-benchmark approach.

Finally, it appears that allowances will be allocated without charge, at least in the early stages of the program, which has been typical of emissions trading systems in other parts of the world, and may lessen political resistance while also sacrificing potential efficiency gains associated with auctioning allowances and recycling revenues.

What’s Unknown about the Chinese Carbon Trading System

Among the key design elements that are unknown as of now (at least to me) are the following:

(6) What is the time-path for expanding the scope of the system to include more sectors, and what sectors will be added?

(7) When and how, if at all, will China seek to link its system with carbon-pricing and other climate policies in other parts of the world?

Given all of these open questions plus the limited sectoral scope of the announced system, it is reasonable to ask: what should we make of all this?

How Significant was the Chinese Announcement?

The announcement, despite all the caveats, was a significant step along the road of climate change policy developments, because the Chinese system will eventually be very important, because of its magnitude and because of the importance of China in CO2 emissions and climate change policy. However, the announcement was not a launch per se, but a statement about a forthcoming launch.

More broadly, the announcement and the eventual launch of the system will have significant effects on other governments around the world – regional, national, and sub-national. Some will be encouraged to launch or maintain their own carbon trading systems, and to increase the ambition of their systems. Why do I say this?

A frequently stated fear of adopting climate policies, including carbon pricing, is the competitiveness effects of those policies, due to emission, economic, and employment leakage. This is more a political issue than a real economic one, but it is nevertheless important. Since the greatest fear in this realm is that domestic factories will relocate to China, that concern will be greatly reduced – or at least it should be – when and if China has put in place a serious climate policy, whether through carbon markets or otherwise.

China is moving slowly and cautiously, which is wise. Not long ago, they were considering launching a system that would initially cover 7,000 companies in several sectors, but the 2017 announcement is of a system that covers 1,700 companies in the electricity sector alone. Of course, it is still important, given that the electricity sector (with its large coal and natural gas plants) accounts for fully a third of China’s CO2 emissions.

During the next two years, the Chinese government – apparently through its National Development and Reform Commission (NDRC), which will administer the trading system – will begin by developing systems for data reporting, registration, & trading – gathering and verifying plant-level emissions data. This will facilitate the establishment of baselines for allocations of allowances. Beyond this, a wide range of rules will need to be established. Following some tests, the actual spot market may launch in 2020 (the same year the Paris Climate Agreement essentially replaces the Kyoto Protocol).

The Path Ahead

As inevitably seems to be the case, the best assessment of this new policy lies somewhere between the extremes. The December announcement by China was neither as exciting as some of the applause from climate activists might suggest, nor was the announcement as meaningless as conservatives have claimed.

Rather, cautious optimism seems to be in order. China is serious about climate change, and is thinking long-term. The country appears to be methodically working to develop a meaningful carbon trading system. What is important now is developing a robust system that can be effective, expanded in scope, and gradually made more stringent. Among the greatest challenges will be achieving the cooperation of the provincial governments, not to mention the compliance of the regulated entities.

Development of the system has begun, with the real launch of trading likely to take place in 2020, which is a key year for Chinese climate policy for other reasons, as well. In that year, China will release its next Five-Year Plan, and it will submit its updated Nationally Determined Contribution to the UNFCCC under the Paris Agreement. What will the United States be doing that year? Not much, just electing a President!

The implication of this famous line (often misquoted as “those who do not learn history are doomed to repeat it”) from philosopher George Santayana’s 1905 book, The Life of Reason, Volume I – Reason in Common Sense, is that we are wise to learn from our mistakes. This is undoubtedly true, as is the parallel recommendation that we are wise to learn from our successes.

In the hope that you may be stimulated to read the full article, in today’s blog essay I draw on the article to provide the historical context of our analysis, and to review some of our conclusions (for the actual analysis of individual cap-and-trade systems, and the justifications for our conclusions, you will need to see the article).

The Historical Context

Thirty years ago, many environmental advocates argued that government allocation of rights to emit pollution legitimized environmental degradation, while others questioned the feasibility of such an approach. At the time, virtually all pollution regulations took a command-and-control approach, specifying the type of pollution-control equipment to be used or setting uniform limits on emission levels or rates.

In the REEP article, Dick Schmalensee and I examined the design and performance of seven of the most prominent emissions trading systems that have been implemented over the past 30 years in order to identify key lessons for future applications. We focused on systems that have been important environmentally and/or economically, and whose performance has been well documented. We excluded emission-reduction-credit (offset) systems, which offer credits for emissions reductions from some counterfactual baseline, because while emissions can generally be measured directly, emissions reductions are unobservable and often ill-defined.

The seven emissions trading systems we examined were:

the U.S. Environmental Protection Agency’s (EPA’s) phasedown of leaded gasoline in the 1980s;

the U.S. sulfur dioxide (SO2) allowance trading program under the Clean Air Act Amendments of 1990;

the Regional Clean Air Incentives Market (RECLAIM) in southern California;

the trading of nitrogen oxides (NOX) in the eastern United States;

the Regional Greenhouse Gas Initiative (RGGI) in the northeastern United States;

California’s cap-and-trade system under Assembly Bill 32; and

the European Union (EU) Emissions Trading System (ETS).

All of these programs except the first are textbook cap-and-trade systems.

In the article, we reviewed the design, performance, and lessons learned from each of the seven systems (and briefly discussed several other cap-and-trade systems). In this blog essay, however, I turn immediately to our summary of key lessons.

Lessons from Thirty Years of Experience

Overall, we found that cap-and-trade systems, if well designed and appropriately implemented, can achieve their core objective of meeting targeted emissions reductions cost-effectively. This is not something that was taken for granted in the past, and is still not accepted in some quarters. That said, the devil is in the details, and design as well as the economic environment in which systems are implemented are very important. Moreover, as with any policy instrument, there is no guarantee of success. Based on the numerous specific lessons we identified in our analysis, several design and implementation features of cap-and-trade programs appear critical to their performance.

Key Features for System Design and Implementation

First, it is important not to require prior approval of trades. In contrast to early U.S. experience with emissions offset systems, transactions costs can be low enough to permit considerable efficiency-enhancing trade if prior approval of trades is not required.

Second, it is clear from both theory and experience that a robust market requires a cap that is significantly below BAU emissions.

Third, to avoid unnecessary price volatility, it is important for final rules (including those for allowance allocation) to be established and accurate data supplied well before commencement of a system’s first compliance period.

Fourth, high levels of compliance in a downstream system can be achieved by ensuring there is accurate emissions monitoring combined with significant penalties for non-compliance.

Fifth, provisions for allowance banking have proven to very important for achieving maximum gains from trade, and the absence of banking provisions can lead to price spikes and collapses.

Sixth, price collars are important. A changing economy can reduce emissions below a cap, rendering it non-binding, or a growing economy can increase emissions and drive allowance prices to excessive levels. Price collars reduce price volatility by combining an auction price floor with an allowance reserve. The resulting hybrid systems will generally have lower costs (as more stable prices facilitate investment planning) at the expense of less certain emissions reductions.

Finally, economy-wide systems are feasible, although downstream, sectoral programs have been more commonly employed.

Political Considerations that Affect Cap-and-Trade Design

Experiences with cap-and-trade also indicate the importance of political considerations for the design of cap-and-trade programs.

First, because of the potentially large distributional impacts involved, the allocation of allowances has inevitably been a major political issue. Free allowance allocation has proven to help build political support. Under many circumstances, the equilibrium allowance distribution, and hence the aggregate abatement costs of a cap-and-trade system, are independent of the initial allowance allocation (Montgomery 1972; Hahn and Stavins 2012). This means that the allowance allocation decision can be used to build political support and address equity issues without concern about impacts on overall cost-effectiveness.

Second, the possibility of emissions leakage and adverse competitiveness impacts has been a prominent political concern in the design of cap-and-trade systems. Virtually any meaningful environmental policy will increase production costs and thus could raise these concerns, but this issue has been more prominent in the case of cap-and-trade instruments. In practice, leakage from cap-and-trade systems can range from non-existent to potentially quite serious. It is most likely to be significant for programs of limited geographic scope, particularly in the power sector because of interconnected electricity markets. Attempts to reduce leakage and competitiveness threats through free allocation of allowances do not per se address the problem, but an output-based updating allocation can do so.

Cap-and-trade systems are now being seriously considered for a wide range of environmental problems. Past experience can offer some guidance as to when this approach is most likely to be successful.

First, the greater the differences in the cost of abating pollution across sources, the greater the likely cost savings from a market-based system – whether cap-and-trade or tax — relative to conventional regulation (Newell and Stavins 2003). For example, it was clear early on that SO2 abatement cost heterogeneity was great, because of differences in ages of plants and their proximity to sources of low-sulfur coal (Carlson et al. 2000).

Second, the greater the degree of mixing of pollutants in the receiving airshed (or watershed), the more attractive a market-based system, because when there is a high degree of mixing, local hot spots are not a concern, and the focus can thus be on cost-effective achievement of aggregate emissions reductions. Most cap-and-trade systems have been based on either the reality or the assumption of uniform mixing of pollutants. However, even without uniform mixing, well-designed cap-and-trade systems can be effective, as illustrated by the two-zone trading system under RECLAIM, at the cost of greater complexity.

Third and finally, since Weitzman’s (1974) seminal analysis of the effects of cost uncertainty on the relative efficiency of price versus quantity instruments, it has been well known that in the presence of cost uncertainty, the relative efficiency of these two types of instruments depends on the pattern of costs and benefits. Subsequent literature has identified additional relevant considerations (Stavins 1996; Newell and Pizer 2003). Perhaps more importantly, theory (Roberts and Spence 1976) and experience have shown that there are efficiency advantages of hybrid systems that combine price and quantity instruments in the presence of uncertainty.

Implications for Climate Change Policy

Two highly relevant lessons from thirty years of experience with cap-and-trade systems stand out. First, cap-and-trade has proven itself to be environmentally effective and economically cost-effective relative to traditional command and control approaches. Moreover, less flexible systems would not have led to the technological change that appears to have been induced by market-based instruments (Schmalensee and Stavins 2013) or the induced process innovations that have resulted (Doucet and Strauss 1994).

Second, and equally important, the performance of cap-and-trade systems depends on how well they are designed. In particular, it is important to reduce unnecessary price volatility, and hybrid designs can offer an attractive option if some variability of emissions can be tolerated, since substantial price volatility generally raises costs.

All of this suggests that cap-and-trade merits serious consideration when regions, nations, or sub-national jurisdictions are developing policies to reduce greenhouse gas (GHG) emissions. And, indeed, this has happened. However, because any meaningful climate policy will have significant impacts on economic activity in many sectors and regions, proposals for such policies have often triggered significant opposition.

It is certainly possible that three decades of high receptivity to cap-and-trade in the United States, Europe, and other parts of the world will turn out to have been only a relatively brief departure from a long-term trend of reliance on command and control environmental regulation. However, in light of the generally positive experience with cap-and-trade, there is reason for optimism that the tarnishing of cap-and-trade in US political debates will itself turn out to be a temporary departure from a long-term trend of increasing reliance on market-based environmental policy instruments. Only time will tell.